Mix dry ingredients (including yeast) in a large bowl
Add sour cream, milk, butter and egg and mix well to form a soft dough
Knead for 10 minutes until smooth and elastic
Transfer dough to a greased bowl, cover with a tea towel and put it in a warm place to double in volume (1 hour)
To check if dough is ready, gently press two fingers in the middle, if an indentation remains, dough has not risen enough
Once dough has risen, make a fist and gently punch dough right in the centre to deflate it, then knead for a minute
Roll out dough onto a lightly floured surface into a rectangle the size of a cookie sheet (50cm x 30cm)
Spread room temp butter all over the dough, leaving a 2cm gap on one of the narrow sides
Combine brown sugar, cinnamon and nutmeg and sprinkle evenly over the butter
Starting opposite of the butterless strip, roll the dough tightly to form an spiral, then gently pinch the seam down to seal, trim the ends for even slices
Cut the dough into even slices around 2cm to make 24 mini rolls or around 4cm to make 12 large ones
Place the rolls in a greased baking dish not touching each other and allow them to rest in a warm place for about 30 minutes for a final rise
Bake at 180*C for 25 minutes or until golden brown, cool on a wire rack
To make the icing, beat butter and sugar until light and fluffy, then beat in milk
When rolls are cool, ice and sprinkle cinnamon to decorate